[Jeff Wilder]

I'm working on a similar simplification, using Pathfinder as the base.

There has to be a balance among all of "usefulness," "realism," and "simplicity," IMO. With an eye on the balance of class skills.

For example, is Sleight of Hand really useful enough to stand on its own? If not (in my games, it's definitely not), what could it be rolled into, to make things simpler? Well, realistically sleight of hand is at least as much about misdirection as it is about a deft touch. So ... what about Bluff? Bluffing is all about misdirection, including the "feint" use of the skill. Why not sleight of hand? The only class that ends up with Sleight of Hand that didn't have it available already is the sorcerer, and I actually really like the idea of the sorcerer as charlatan, so bonus.

Directly from your list, along these lines, I've never played in a game where Ride was important enough to stand on its own. So I've folded it into Handle Animal. (Why should whether or not you can get an animal to do something depend so much on whether you're physically atop it?)

I am also considering -- in an instance of great minds thinking alike -- folding Climb, Jump, and Swim into, you guessed it, Athletics.